Filter insertion loss measuring system
By introducing bias power supply and loading test modules into the filter insertion loss measurement system, the problem of inaccurate measurement in the prior art is solved, and accurate and flexible measurement of protective filter insertion loss is achieved, thereby improving the reliability of filter design.
Patent Information
- Application Number
- CN202422145661.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-02
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-09-02
AI Technical Summary
The prior art is in measuring the insertion loss of an integrated protection filter, and the conditions are single, and the dynamic measurement requirements of the protection filter cannot be met, resulting in inaccurate measurement.
The bias power supply and loading test module are adopted to realize insertion loss measurement under different signal types and loading conditions. Through the decoupling network and multiple signal mode test modules, the accuracy and flexibility of measurement are improved.
It improves the measurement accuracy of the protective filter insertion loss, meets the needs of dynamic design verification, and enhances the reliability of the filter design.
Smart Images
Figure CN223038055U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of insertion loss measurement, and in particular to a filter insertion loss measurement system. Background Art
[0002] With the development of science and technology, electronic and electrical equipment is developing towards multi-function, high power and small size. However, the greater the power and smaller the size of electronic and electrical equipment, the more serious the electromagnetic interference problem. As the main means of electromagnetic interference suppression, with the development of filter design technology, integrated protection filters have become an important technical development direction in order to protect filter equipment, which brings with it the problem of characteristic verification and measurement accuracy of integrated protection filters.
[0003] At present, the test conditions for the traditional integrated protection filter solution are relatively simple. The filter insertion loss is tested under the condition of 50 ohms without bias system, and the common mode and differential mode insertion loss can be tested. However, the test under this condition mainly verifies the insertion loss of the filter under signal conditions, which is insufficient for filters with protection types. Because the surge protection circuit in the protection filter device generally requires a driving voltage of 6-8V to work, this signal-type insertion loss verification cannot meet the overall product insertion loss requirements. The suppression characteristics of the filter itself are jointly determined by the filter circuit characteristics, loading, etc. However, the current traditional method is static measurement, and lacks consideration of the filter in a dynamic measurement environment.
[0004] The traditional test scheme is relatively simple and can only measure the insertion loss under specified test conditions. However, there are differences between the parameters in actual use and the parameters under the specified test conditions, resulting in inaccurate insertion loss measurements. Utility Model Content
[0005] In order to improve the measurement accuracy of the protection filter insertion loss, the present application provides a filter insertion loss measurement system.
[0006] The present application provides a filter insertion loss measurement system, which adopts the following technical solution:
[0007] A filter insertion loss measurement system comprises a loading test module and a bias power supply, wherein the loading test module is connected in series with the bias power supply and a filter under test, and the loading test module is used to measure the insertion loss of the filter under test under the loading condition of the bias power supply.
[0008] By adopting the above technical solution, a bias power supply is set, and the bias power supply can realize AC and DC loading, thereby realizing the measurement of the insertion loss of the measured filter in the loaded state, thereby improving the measurement accuracy of the protection filter insertion loss.
[0009] In a possible implementation, the system further includes a single-pole double-throw switch and a signal mode test module. The fixed end of the single-pole double-throw switch is connected to the input end of the input signal. The movable end of the single-pole double-throw switch is respectively connected to the signal mode test module and the loading test module. The signal mode test module is used to measure the insertion loss of the filter under test under different signal types.
[0010] In a possible implementation, the signal mode test module includes at least two of a common-mode test module, a differential-mode test module, and a normal-mode test module. The common-mode test module, the differential-mode test module, and the normal-mode test module are connected to the input end of the input signal through a single-pole multi-throw switch. The common-mode test module is used to measure the insertion loss of the filter under test when the input signal is a common-mode signal. The differential-mode test module is used to measure the insertion loss of the filter under test when the input signal is a differential-mode signal. The normal-mode test module is used to measure the insertion loss of the filter under test when the input signal is a normal-mode signal.
[0011] In a possible implementation, the common-mode test module includes a common-phase input transformer and a common-phase output transformer. The input end of the common-phase input transformer is connected to the input end of the input signal. The output end of the common-phase input transformer is connected to the input end of the filter under test. The input end of the common-phase output transformer is connected to the output end of the filter under test. The output end of the common-phase output transformer outputs a loss signal, and the loss signal is used to reflect the insertion loss of the filter under test.
[0012] In a possible implementation, the differential-mode test module includes an anti-phase input transformer and an anti-phase output transformer. The input end of the anti-phase input transformer is connected to the input end of the input signal. The output end of the anti-phase input transformer is connected to the input end of the filter under test. The input end of the anti-phase output transformer is connected to the output end of the filter under test. The output end of the anti-phase output transformer outputs a loss signal, and the loss signal is used to reflect the insertion loss of the filter under test.
[0013] In a possible implementation, the loading test module is a decoupling network.
[0014] In a possible implementation, the common-phase input transformer and the common-phase output transformer have the same model.
[0015] In a possible implementation, the anti-phase input transformer and the anti-phase output transformer have the same model.
[0016] In a possible implementation manner, the system further includes a shielding housing, and a plurality of shielding bins are arranged inside the shielding housing.
[0017] In summary, the present application includes the following beneficial technical effects:
[0018] By providing a bias power supply, the bias power supply can achieve the loading of alternating current and direct current, and further realize the measurement of the insertion loss of the filter under test in the loading state, improving the measurement accuracy of the insertion loss of the protective filter. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 is a system block diagram of a filter insertion loss measurement system provided by an embodiment of the present application.
[0020] Figure 2 is a circuit structure diagram of a filter insertion loss measurement system provided by an embodiment of the present application.
[0021] Figure 3 is a schematic structural diagram of a shielding housing provided by an embodiment of the present application.
[0022] Figure 4 is a schematic internal structure diagram of a shielding housing provided by an embodiment of the present application.
[0023] Description of reference numerals: 10, loading test module; 20, bias power supply; 30, filter under test; 40, single-pole double-throw switch; 50, signal mode test module; 51, common-mode test module; 52, differential-mode test module; 53, normal-mode test module; 54, single-pole multi-throw switch; 60, shielding housing; 61, shielding bin. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0024] The following further Figures 1-4 describes the present application in detail with reference to the accompanying drawings.
[0025] At present, the common method for verifying the characteristics of an integrated protective filter is to measure the insertion loss under the condition of no loading of 50 ohms. The core idea of this test method is to use the two level values measured before and after insertion, and calculate the difference between the two level values to obtain the insertion loss of the device under test, which is mainly used for quality consistency inspection under specific conditions. However, in the actual use process of the protective filter, it will not always be in the above specific conditions. This measurement method cannot play an actual guiding role in the specific design of the actual interference suppression of the protective filter, the verification of magnetic core saturation, etc.
[0026] Traditional measurement methods ignore the influence between different connection terminals, which easily leads to an overestimation of the differential-mode loss test, and do not consider insufficient shielding during test verification, which has an impact on the common-mode insertion loss test and results in a smaller test result.
[0027] The present application provides a filter insertion loss measurement system. By increasing current loading and adding bias testing during insertion loss measurement, voltage and current are applied simultaneously to the filter, enabling the measurement of the insertion loss of the filter under different measurement conditions, meeting the dynamic design verification of the filter, improving the accuracy of insertion loss measurement, and enhancing the reliability of filter design.
[0028] An embodiment of the present application discloses a filter insertion loss measurement system. Referring to Figure 1 and Figure 2 , the filter insertion loss measurement system includes a loading test module 10 and a bias power supply 20. The loading test module 10 is connected in series with the bias power supply 20 and the filter under test 30. The loading test module 10 is configured to measure the insertion loss of the filter under test 30 under the loading condition of the bias power supply 20.
[0029] The bias power supply 20 can achieve AC and DC loading, and at the same time, anti-reverse connection and current protection functions are added to improve the high reliability of the module. The input uses an electrical connector, and the output end uses different series of connection wires.
[0030] Further, the loading test module 10 is a decoupling network. In a specific embodiment, the loading test module 10 includes a loading input unit and a loading output unit. The loading input unit includes a capacitor C1, an inductor L4, and a capacitor C2. The loading output unit includes a capacitor C1', an inductor L4', and a capacitor C2'. The input signal enters from one end of the capacitor C1. The other end of C1 (loading input 1) is connected to the filter under test 30. The other end of C1 is also connected in series with the inductor L4 and the capacitor C2. The free end of the capacitor C2 is grounded. The common connection end of the inductor L4 and the capacitor C2 is connected to the bias power supply 20. The input signal enters the filter under test 30 through C1, and after output from the filter under test 30, it enters the loading output unit through loading output 1' and then outputs a loss signal. The loss signal is used to reflect the insertion loss of the filter under test 30. The connection relationship of each component in the loading output unit is symmetric with respect to the bias power supply 20 and / or the filter under test 30, which will not be elaborated here. The loading input 1 and the loading output 1' are reserved test connection points for connecting the filter under test 30.
[0031] In the embodiment provided by the present application, the loading test module 10 is mainly a decoupling network formed by the bias power supply 20, the loading input unit, and the loading output unit. C2 and C2' use large-capacitance capacitors to block direct current. The inductor L4 uses an inductor with a large saturation degree to pass direct current and block alternating current. There is a coupling effect between C1 and C1'.
[0032] The above filter insertion loss measurement system further includes a single-pole double-throw switch 40 and a signal mode test module 50. The fixed end of the single-pole double-throw switch 40 is connected to the input end of the input signal. The movable end of the single-pole double-throw switch 40 is respectively connected to the signal mode test module 50 and the loading test module 10. The signal mode test module 50 is used to measure the insertion loss of the filter under test 30 under different signal types.
[0033] Further, the signal mode test module 50 includes at least two of a common-mode test module 51, a differential-mode test module 52, and a normal-mode test module 53. In the embodiment provided in the present application, the signal mode test module 50 includes a common-mode test module 51, a differential-mode test module 52, and a normal-mode test module 53. The common-mode test module 51, the differential-mode test module 52, and the normal-mode test module 53 are connected to the input end of the input signal through a single-pole multi-throw switch 54. The common-mode test module 51 is used to measure the insertion loss of the filter under test 30 when the input signal is a common-mode signal. The differential-mode test module 52 is used to measure the insertion loss of the filter under test 30 when the input signal is a differential-mode signal. The normal-mode test module 53 is used to measure the insertion loss of the filter under test 30 when the input signal is a normal-mode signal.
[0034] Further, the common-mode test module 51 includes a common-phase input transformer and a common-phase output transformer. The input end of the common-phase input transformer is connected to the input end of the input signal. The output end of the common-phase input transformer is connected to the input end of the filter under test 30. The input end of the common-phase output transformer is connected to the output end of the filter under test 30. The output end of the common-phase output transformer outputs a loss signal. The loss signal is used to reflect the insertion loss of the filter under test 30. The common-phase input transformer and the common-phase output transformer have the same model.
[0035] In a specific embodiment, when the single-pole double-throw switch S1 is moved to the connection point of the single-pole multi-throw switch S2, S2 is connected to L1, that is, the common-mode test module 51 is used to measure the insertion loss of the filter under test 30. The connection between the test connection point "input L" and the input end of the filter under test 30 is tested, and the connection between the test connection point "output L'" and the output end of the filter under test 30 is tested. The input signal passes through the common-phase input transformer L1, the filter under test 30, the common-phase output transformer L1', and the single-pole multi-throw switch S2', and the loss signal is output from the single-pole double-throw switch S1'.
[0036] Further, the differential mode test module 52 includes a phase - difference input transformer and a phase - difference output transformer. The input end of the phase - difference input transformer is connected to the input end of the input signal. The output end of the phase - difference input transformer is connected to the input end of the filter under test 30. The input end of the phase - difference output transformer is connected to the output end of the filter under test 30. The output end of the phase - difference output transformer outputs a loss signal, and the loss signal is used to reflect the insertion loss of the filter under test 30. The phase - difference input transformer and the phase - difference output transformer have the same model.
[0037] In a specific embodiment, when the single - pole double - throw switch S1 is moved to the connection point of the single - pole multi - throw switch S2, S2 is connected to L2, that is, the differential mode test module 52 is used to measure the insertion loss of the filter under test 30. The test connection point "input L" is connected to the input end of the filter under test 30, and the test connection point "output L'" is connected to the output end of the filter under test 30. The input signal passes through the phase - difference input transformer L2, the filter under test 30, the phase - difference output transformer L2', and the single - pole multi - throw switch S2', and the loss signal is output from the single - pole double - throw switch S1'.
[0038] In other embodiments, the filter under test 30 can also be connected to the signal mode test module 50 through the test connection points "input N" and "output N'", or other test connection points can be used, which are not limited herein.
[0039] The common mode test module 53 is mainly used to verify the signal attenuation effect of the port test part. The common mode test module 53 includes L3, L3', R1, and R1'. Among them, L3 and L3' are in - phase transformers of the same model.
[0040] In the embodiment provided by the present application, the connection ports of the above - mentioned test connection points use BNC connectors, and the connection ports for connecting the filter under test 30 use serialized ports, including various connection methods such as terminals, connecting wires, and connection bolts, making the connection of each connection port relatively stable and ensuring the stability of the test to a certain extent. The connecting wires used between the above - mentioned modules or connection ports are RF cables, which can maintain the impedance consistency in the connection line to the greatest extent.
[0041] The above - mentioned system further includes a shielding housing 60, and a plurality of shielding compartments 61 are arranged in the shielding housing 60.
[0042] In the embodiments provided by the present application, the shielding housing 60 is connected by a sheet metal structure, which can not only achieve an integrated design but also reduce impedance and effectively shield. The interior of the shielding housing 60 adopts a partition form, dividing the interior of the shielding housing 60 into multiple shielding compartments 61. The circuit modules arranged in each shielding compartment 61 are different. For example, a loading test module 10, a bias power supply 20, a filter under test 30, a common-mode test module 51, a differential-mode test module 52, and a normal-mode test module 53 are sequentially arranged in the shielding compartment 61. The circuit modules arranged in each shielding compartment 61 are set according to actual requirements. By providing the shielding compartments 61, shielding between the various circuit modules is achieved, reducing the mutual influence generated between the various circuit modules when measuring the insertion loss.
[0043] The implementation principle of a filter insertion loss measurement system according to an embodiment of the present application is as follows: First, by providing the bias power supply 20, the measurement of the insertion loss of the filter under test 30 under a loaded state is achieved, improving the accuracy of the insertion loss measurement. At the same time, the obtained measurement results can also provide guidance for parameter design of the filter, etc. Second, through a single-pole multi-throw switch 54, the common-mode, differential-mode, and normal-mode measurements are placed in the same system, facilitating the corresponding measurements under different measurement requirements and improving the simplicity of the insertion loss measurement. Finally, by providing multiple shielding compartments 61, shielding between the various circuit modules is achieved, avoiding interference during the measurement process and indirectly improving the accuracy of the insertion loss measurement.
[0044] The above are all the preferred embodiments of the present application. The protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.
Claims
1. A filter insertion loss measurement system, characterized in that: The invention comprises a loading test module (10) and a bias power supply (20), wherein the loading test module (10) is connected in series with the bias power supply (20) and a filter under test (30), and the loading test module (10) is used to measure the insertion loss of the filter under test (30) under the loading condition of the bias power supply (20).
2. The filter insertion loss measurement system according to claim 1, characterized in that: The system further comprises a single-pole double-throw switch (40) and a signal mode test module (50), wherein the fixed end of the single-pole double-throw switch (40) is connected to the input end of the input signal, and the movable end of the single-pole double-throw switch (40) is respectively connected to the signal mode test module (50) and the load test module (10), and the signal mode test module (50) is used to measure the insertion loss of the filter under test (30) under different signal types.
3. The filter insertion loss measurement system according to claim 2, characterized in that: The signal mode test module (50) comprises at least two of a common mode test module (51), a differential mode test module (52) and a normal mode test module (53); the common mode test module (51), the differential mode test module (52) and the normal mode test module (53) are connected to an input end of an input signal via a single-pole multi-throw switch (54); the common mode test module (51) is used to measure the insertion loss of the filter under test (30) when the input signal is a common mode signal; the differential mode test module (52) is used to measure the insertion loss of the filter under test (30) when the input signal is a differential mode signal; and the normal mode test module (53) is used to measure the insertion loss of the filter under test (30) when the input signal is a normal mode signal.
4. The filter insertion loss measurement system according to claim 3, characterized in that: The common mode test module (51) comprises a common-phase input transformer and a common-phase output transformer, wherein the input end of the common-phase input transformer is connected to the input end of the input signal, the output end of the common-phase input transformer is connected to the input end of the filter under test (30), the input end of the common-phase output transformer is connected to the output end of the filter under test (30), and the output end of the common-phase output transformer outputs a loss signal, wherein the loss signal is used to reflect the insertion loss of the filter under test (30).
5. The filter insertion loss measurement system according to claim 3, characterized in that: The differential mode test module (52) comprises an out-of-phase input transformer and an out-of-phase output transformer, the input end of the out-of-phase input transformer being connected to the input end of the input signal, the output end of the out-of-phase input transformer being connected to the input end of the filter under test (30), the input end of the out-of-phase output transformer being connected to the output end of the filter under test (30), and the output end of the out-of-phase output transformer outputting a loss signal, the loss signal being used to reflect the insertion loss of the filter under test (30).
6. The filter insertion loss measurement system according to claim 1, characterized in that: The loading test module (10) is a decoupling network.
7. The filter insertion loss measurement system according to claim 4, characterized in that: The same-phase input transformer and the same-phase output transformer are of the same model.
8. The filter insertion loss measurement system according to claim 5, characterized in that: The out-of-phase input transformer and the out-of-phase output transformer are of the same model.
9. The filter insertion loss measurement system according to any one of claims 1 to 8, characterized in that: The system further comprises a shielding shell (60), wherein a plurality of shielding chambers (61) are arranged in the shielding shell (60).